Propelling pencil



Sept. 19, 1939. l.. KRAEMER 2,173,279

PROPELLING PENCIL Filed sept, ze; 193'? 2 sheets-sheet 1 Patented Sept.19, 1939 UNITED STATES PATENT OFFICE Application September 2 8, 1937,Serial No. 166,055

In Italy October 1, 1936 2 Claims.

' '5 zine, relative to its support in any position, either in writingposition, or in retracted position.

The locking device consists of a slider serving as support for the leadfor example to an elastic socket or to a springl carrying the lead, thisslider l being provided on the inside withA a wedging meinber forexample a ball which can be pused by a spring along an inclined plane ofthis slider in such a manner as to produce, in co-operation with theinternal surface of the barrel of the 16 pencil, a constant contact ofthe balll between this plane and this surface.

'Ihe slider has the shape of a shuttle with a plane inclined fromthefront towards. the rear for a short distance of the bottom of thislslider 20 lwhich has at the rear a wall against which the spring abuts.v

To cause the lead to project outside the barrel 'use is made of a sleevemounted on the barrel and provided with a Awing which projects 25through a longitudinal `slot in the barrel, towards the interior of thelatter and exactly in the space between the inclined plane and the ballserving for .the wedging. 'I'he wing of this sleeve in pushing againstthe inclined plane'pushes `forward 30 the slider with the support forthe lead.

During this forward movement of the slider the ball tries to descendalong the inclined plane by the amount which suffices to avoid allwedg'ing.

Inorder to retract the lead the socket is pulled 35 backwards and thenthe internal wing prevents the wedgingof the ball and pulls back theslider towards the rear by the intermediation of a Spring.

The locking device formed by the spring, bythe 40 ball, by the inclinedplane of the slider and by the internal surface of the barrel remains innormal condition always ready to function.

. The invention will be readily understood with the aid of the followingdetailed description which 45 refers to the annexed drawings of one formof construction given by way of example only.

Fig. 1 shows the sliding lead pencil, provided with the new lockingdevice, in perspective view; Fig. 2 shows a fragmentary longitudinal 50section, the operating ring being omitted; Fig. 3 1

shows the working of the locking whilst the lead is being retracted.;Fig. 4 shows the working of the pencil while the lead is being advanced;Fig. 5 shows a transverse section on the line A-B of 55 Fig. 4; Fig. 6is a transverse section on the line (Cl. 1Z0-19) C--D of Fig. 3; Fig. 7is a transverse section on the line E-F of Fig. 3.

Figs. 816 `show a sliding vided with a different construction of lockingdevice and more exactly: Fig. 8 shows a perspective view of the pencil;Fig. 9 shows a section of the pencil while the Aring. is drawn back witha View `to retracting the lead; Fig. l0 shows a section during thepushing forward of the lead; Fig. 11 shows on a larger scale the wedgingdisc in two positions; Fig.` 12 shows-the transverse section ofthebarrel; Fig. 13 shows an axial section of the ring which moves the lead;Fig. 14 shows a transverse sec-` tion of the moving tongue mounted onthe barrel and surrounded by a ring which moves it; Fig. 15 shows thewedging disc; Fig. 16 shows a perspective view of the tongue with itstwo wings.`

Referring particularly to the figures .of the drawings: A

I is the barrel of the pencil provided with a 4longitudinal slot; 3 is aslider in the shape of a lead pencil pro` shuttle having a base providedwith a sloping surface 4.

In 4the hollow of this shuttle is housed aspiral spring 6 which abutsagainst a ball I and against the rear wall 5 of the shuttle. 'Ihe ball Ican- `not reascend completely the length of the inclined surface II,because up above it meets the internal surface of the barrel I. Thiswedging produces a transverse thrust on the shuttle 3 which sticksenergetically against the barrel. The spring 6 pressing against the ball'I assures the locking action of the shuttle in Aall positions withrespect to the barrel I. The sliding shuttle 3 may carry the lead 9 bymeans of a very flexible metal spiral spring I0. This spiral springserves vto assure the ilexibility of support of the lead during writing.l In order to advance the lead la ring Iiis provided slidably mounted onthe barrel I and provided with an internal, radially /directed tongueI2, and traversing the. slot 2 which serves as a guide.

Thistongue I2 during its longitudinal movements may abut against theinclined plane Ily (Fig. 4) and it moves the shuttle 3 forwards andthereby also` the lead 9. If on the other hand lthe ring II-moves back,the tongue I2 pushes the ball 1 which, by the intermediation of thespring 6, abutting against the wall 5, pushes the shuttle 3 backwards,ask the ball 1 ceases to wedge energetically against the internalsurface of the barrel I. f

The lead-carrying spiral spring IIJ may also be lreplaced by anothermember, elastic, semi-elastic or rigid. y

The barrel of the pencilnnay also have any other shape different fromthe cylindrical form with point. The shuttle may also have a formdiierent from that indicated provided that the wedging device issubstantially the same.

According to the construction shown in Figs. 8-16:

I3 is a tongue introduced into the slot 2 and supported by two wings I3,Illa, I3b, on the barrel I'; I2' is a moving ring with two internalflanges I2'a, I2b, serving to move the tongue I3. This tongue I3projects into the shuttle 3 of which the rear wall 5 is brought veryclose to the tongue I3.

A slight movement of this tongue is sufficient to encounter the disc I4which finally encounters the wall 5.

When the pencil is inclined with its point downwards, the surface'oi thedisc i4 touches the internal wall of the barrel I and if thepoint issupported on the paper, the inclined plane I5 produces its Wedging. Inthis position the disc I passes into the position I4 and producestheeiect of locking the shuttle 3 against the internal wall of the barrel.

This construction is more economical because it does away with thespring, and because the disc I4 may be made by cutting froma sheet.

I claim:

1. In a. mechanical pencil, a longitudinally slotted casing, a leadholder provided with a tapered surface slidably arranged within saidcasing, a clamping roller arranged between the inner wall of said casingand tapered surface of said holder, a ring member with an innerprojection slidably mounted upon the slotted casing, the projectionpassing through the casing slot and entering the zone between saidroller and apex of the tapered surface of said lead holder in order todisengage said roller from its clamping position on retracting of saidring member.

2. In a mechanical pencil, a longitudinally slotted casing, a leadholder with a tapered surface slidably arranged in said casing, a.clamping roller arranged between the inner wall of said casing'andtapered surface of said holder, a ring member provided with an innercircular groove slidably mounted upon said casing, a curved sheet metalstrip with an inner projection arranged in the groove of the ring, theinner projectionvof said strip passing through the casing slot andentering the zone between said roller and apex of the tapered surface ofsaid roller adapted to disengage said roller from its clamping positionon retracting of said ring member.

LODOVICO KRAEMER.

